EIA estimates that the total inventory of alternative fuel vehicles (AFVs) in fleets in 2009 was about 826,318, up about 7% from 2008. Despite this growth, the availability of potential AFVs does not equate to actual use of AFVs because of uneven access to transportation fuels, specifically for ethanol.

The limited availability and economic viability of E85 fuel means that the vast majority of AFVs owned by individuals burn traditional fuels (gasoline and diesel). Gasoline and diesel electric hybrids are not AFVs as defined in the Energy Policy Act of 1992; their predominant fuel source is not an alternative fuel.

Vehicles consuming alternative transportation fuels are primarily part of fleets owned by Federal, State and local governments; fuel providers; transit agencies; or other private entities, where access to an alternative fuel has been established in response to various legislative regulations, incentives, and environmental interests.